Field of Invention
The present invention relates to a soap dispensing device, and more particularly to an automatic soap foam/liquid soap dispenser.
Description of Related Arts
The liquid soap dispenser is a bathroom electric appliance for automatically dispensing the liquid soap when washing hand, so as to avoid the secondary pollution. In a place such as a public restroom, the liquid soap dispenser is generally arranged for squeezing the hand sanitizer out. For the conventional liquid soap dispenser, the liquid soap is squeezed out through a soap bag liquid squeezing device. However, the squeezing soap bag is done manually, which is inconvenient; and a direct contact to the liquid soap dispenser by the hand is insanitary.
The Chinese patent application, CN200320123483.1, is a human body induction liquid soap dispenser, comprising an outer case in which a cavity is provided, wherein: a soap bag liquid squeezing device is connected to the bottom part of the outer case and next to the provided cavity; an infrared sensor and a corresponding control circuit are connected to the bottom part of the outer case; a small motor connected with the control circuit is also connected to the bottom part of the outer case, and the output shaft of the small motor is connected with a reciprocating motion mechanism through a gear reducer; and, the reciprocating motion mechanism along with the soap bag liquid squeezing device forms an infrared sensing liquid discharging device. During use, when the hand is placed close to the infrared sensor, the small motor is triggered to work and automatically squeezes the soap bag liquid squeezing device to discharge the liquid, which is convenient, avoids a direct contact with the dispenser, and greatly increases the degree of cleanness when used in the public place. However, the soap bags have a short service life and are easy to be damaged, and if the control of the liquid discharge amount is inaccurate, a great waste is usually caused.
Later, people designed the cylinder-type liquid squeezing device. The output gear is driven by the motor, and then the liquid squeezing device is driven to discharge the liquid, and the liquid discharge amount is accurately controlled and the service life of the dispensers has increased a lot. The dispensers having such an operation principle can be classified into two categories by angle. In the case of the first category, the output gear of the gearbox rotates 180 degrees to complete the pumping action, then rotates another 180 degrees to realize the sucking process of the pump body. The advantages are that the motor does not change directions, the speed of the output gear is fast, and the gear ratio is low, while the disadvantages are that the working current is high, and the liquid discharge amount cannot be automatically adjusted. In the case of the second category, the output gear of the gearbox rotates by an acute angle to accomplish the pumping action, and then reversely rotates by the acute angle to realize the sucking action of the pump body. The difference is that the motor reverses. However, the currents, generated at an initial point and an end point of the acute angle, are high lock rotor motor currents, and only when the control circuit senses the high surging current, the motor is controlled to reversely rotate, causing the slow speed of the output gear and the high gear ratio. The disadvantages are that the high lock rotor motor currents are generated, and the discharge liquid amount cannot be adjusted.